The longitudinal growth trajectory of children with congenital hypothyroidism during the first 3 years of life.

Congenital hypothyroidism (CH) is detected through a newborn screening program in Iran, enabling early detection and prompt treatment. This study addresses the longitudinal growth trajectory of Iranian children with CH and explores associated factors during the first 3 years of life. Data from 1474 children with CH in Isfahan, Iran (2002-2022), were analyzed. Weight, height, and head circumference were measured, and z-scores for age were calculated. Group-based trajectory modeling was applied to distinct growth trajectories. Factors influencing growth patterns, including gender, treatment initiation age, delivery method, parental consanguinity, history of familial hypothyroidism, and thyroid-stimulating hormone (TSH) levels at 3-7 days, were investigated. Thirty-seven percent of children diagnosed with CH faced a delay in weight, while 36.6% experienced stunted height, and 25.7% showed a retardation in head circumference growth. The initiation of treatment, parental consanguinity, and family history of hypothyroidism varied among these groups. Children exhibiting an optimal growth pattern in the initial 3 years of life demonstrated lower average TSH levels.

conclusionThis research emphasizes the complexity of managing CH and stresses the importance of tailoring interventions based on individualized characteristics and the ongoing growth patterns of the children. Future research is required to understand the intricate relationships between growth patterns and various determinants and optimize the growth and developmental outcomes of children with CH. WHAT IS KNOWN: • Iran has a higher prevalence of congenital hypothyroidism (CH) with a nationwide screening program. • There are concerns about delayed growth in CH children, but limited research on long-term patterns and contributing factors. WHAT IS NEW: • Distinct patterns in weight, height, and head circumference among children with CH were identified. • Factors such as consanguinity, parental hypothyroidism, and TSH levels impact growth outcomes. • CH management is complicated, and there is a need for individualized interventions.